head to head
Doom (1993) asks more than Half-Life 2, and the gap is execution.

Execution · Pure Mechanics
A test of fast, precise shooting and map navigation against scripted but relentless enemies.

Execution · Pure Mechanics
Landmark FPS built on physics puzzles and tight gunplay.
Doom (1993) leans Execution (Pure Mechanics); Half-Life 2 leans Execution (Pure Mechanics).
Doom (1993) leans clearly harder on execution.
Doom (1993)
Precise movement and shooting against relentless enemy pressure
Half-Life 2
Gravity gun and shooting demand precision.
Half-Life 2 leans a little harder on reads, though the gap is small.
Doom (1993)
Enemies follow scripted patrol and attack patterns, not adaptive
Half-Life 2
Combine AI scripted, non-adaptive.
Doom (1993) leans clearly harder on variance.
Doom (1993)
Enemy placement is fixed but unknown on first run through levels
Half-Life 2
Almost no randomness.
Doom (1993) leans clearly harder on optimization.
Doom (1993)
Level routing and resource management determine survival efficiency
Half-Life 2
Linear progression with no builds.
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.